Process of treating sugar juices



Patented June 9, 1936 I UNITED STATES 2,043,911 PROCESS OF SUGAR JUICES Emil K. Vcntrc, Washington, D.

Henry A. Wallace, as Secretary Q, assignor to of Agriculture of the United States of America No Drawing. Application March 6, 1936, Serial No. 67,493

3 Claims. (Cl- 127-46) (Granted under the act of March 3, amended April 30, 1928; 3'10 0. .G.

- This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described, if patented, may be manufactured and used by or for 5 the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to the manufacture of improved quality granulated sugar in cane sugar and beet sugar factories and to the production of better quality sirups and molasses from sugar cane. The manufacture of direct-consumption cane and beetsugars by the sulphitation, sulphitation lime phosphoric acid, and the carbonation-sulphitation processes is well understood and needs no elaboration here. It is typical, as is commonly known by sugar technologists, that sugars, sirups, and molasses made by the use of sulphitation contain measurable quantities of sulphites. For example, sulphitation sugars vary in sulphite content from about 1 to 75- parts per million, while commercial grades of edible cane molasses commonly contain 50 to 500 parts of S02 per kilo. The presence of residual SO: in the sugar is considered undesirable from the standpoints of keeping quality and general trade acceptance, while in the case of sugarcane sirup and molasses, sulphites impart an objectionable flavor.

The principal object of this invention is to remove the sulphite ion from products made from sugarcane and sugar beets whenever the sulphitation process in any of its formsis used in manufacture. I

I have found that an oxidizing agent, for example, chlorine, bleaching powder, and substances containing available chlorine, may be used to remove or convert sulphites in the sulphitation process of manufacturing products from sugarcane and sugar beets. The oxidizing agent may be used at any point in the manufacturing process following the actual sulphitation, andmay be applied in suilicient proportion to remove all or any desired portion of the sulphite ion. I have found that sugars of improved quality result from the use of this method, and that sugarcanesirup and molasses of more pleasant and desirable flavor may thus be produced. Sugars of lower sulphite content result, and the characteristic tartness or sulphite "tang may thus largely be eliminated from sirups and molasses. Q

To illustrate the method of applying the oxidizing agent, although not limiting the process to these particular details, the following examples are given: In applying my process for the conversion or removal of sulphites in the products of sulphitation sugar or sirup manufacture available chlorine is the active agent used. This agent may be added to the products either directly as a gas or in aqueous solutions, or by use of hypochlorites.

I shall specify hypochlorites in the examples here given, it being understood that chlorine gas can be substituted for the hypochlorite in each example providing a chlorinator for measuring and applying the gas is made available.

In applying the process for the conversion or removal of sulfites fromsugars either from the first or subsequent crystallizations, it is most convenientto apply the chlorine as a hypochlorite solution'in the centrifugal wash water as follows: A solution of commercial calcium hypochlorite containing to '70 per .cent available chlorine is made up, allowed to settle and insoluble material removed by decantation. It is desirable to have this solution of such a strength that two litres will contain the soluble material from 50 grams of the commercial calcium hypochlorite. It is difficult to state empirically the quantities for all cases, due to local variations in the use of the sulphitation process. However, by trial itwas determined that quantities of 2550 grams of commercial calcium hypochlorite per 40 inch centrifugal were ample. The solution of hypochlorite is mixed with the regular amount of sugar wash water and the sugar washing operation carried on in the usual manner. This leaves a hyp'ochlorite solution adhering to the sugar crystals and reaction proceeds in the usual process 6 to 12 hours, or until the sugar is dried in the granulator. y

In applying my process for the conversion or removal of sulphites from sirup made by the sulphitation process, the removal of sulphites may be effected in the finished sirup or inthe semisirup if this process is used.

In applying my process to the conversion or removal of sulphites from molasses, it is necessaryto determine the quantity of hypochlorite needed by trial in the following manner: I

To a weighed amount of molasses, as it comes from the centrifugals, diluted to 32 Baum with water, a known strength of calcium hypochlorite solution is added with thorough mechanical mixing. As a test for suflicient hypochlorite addition, a distinct blue color should be obtained on adding 15 per cent potassium iodide solution and starch solution indicator. As it is'common practice to dilute the molasses to 32 Baum and allow it to settle 6 to 12 hours or longer before boiling to density, I find it very much facilitates mix ing 01' hypochlorite solution with molasses if it is added at the intake of the molasses pump behind the centrifugals. This can best be done by making the hypochlorite solution up to a volume of twenty gallons, using. the quantity of hypochlorite found by calculation to be sumcient for the molasses from the entire strike of sugar. A small I adjustable cock is put on the hypochlorite container and a small steady stream is mm in with the stream of dilution water so that the discharge from pump is 32 Baum and gives a test for sut- I claim:

1. In the manufacture oi products from sugarcane and sugar beets by of sulphitation, the step which comprises app ng an oxidizing agent containing available chlorine to remove or convert sulphites. p

2. In the manufacture of products from sugarcane and sugar beets by use of sulphitation, the step which comprises applying chlorine to remove or convert sulphites.

3. In the manuiacture oi products from sugarcane and sugar beets by use of sulphitation, the step which comprises applying a hypochlorite to remove or convert sulphites.

, EMJL K. VEN'I'RE. 

